Chocolate, fatty Christmas foods, and non-food items like gift paper and tape can be life-threatening for dogs. Chocolate is highly toxic and even small amounts can cause heart problems or death in dogs. The rich, heavy holiday foods can cause diarrhea and vomiting. Gift paper and tape should also be kept out of reach, as ingestion may require surgical removal. Adding beneficial bacteria to a dog's water can help soothe an upset stomach from unsafe ingestions.